iChart 2000

The first Near Vision Testing App ...

Only £21.99

iChart2000 turns and iPhone into a powerful and versatile vision assessment tool for Optometrists, Ophthalmologists, Orthoptists and other eye care professionals. The App offers an unrivalled suite of test charts and vision tests for both distance and near vision testing

The App includes a huge range of tests and stimuli. These are categorised into four modes:

Near tests: A large selection of tests designed for assessing “near vision”. The iPod or iPhone is held at a typical reading distance (e.g. 40cm) for these tests.

3m tests : A range of tests and stimuli designed to be viewed from 3 metres. These may be used within the consulting room or for domiciliary testing.

Patient information: A selection of images and a video to help explain various eye conditions to patients.

Calculators: A number of calculators to help with those tricky optical calculations

A more detailed look at the features ...

Reading tests: This group displays conventional reading test types calibrated in point size (N5, N6, N8 etc.) where the point size refers to the height of the body of the letters in units of 1/72 of an inch.By rotating the iPod/iPhone passages of text suitable for children and adults can be displayed. Text size is changed by simply stroking the screen.

Near LogMAR reading charts: At last - a sensible way to measure near visual acuity. Rows of text are arranged according to the logMAR format.

Near LogMAR chart: Selecting this option displays logMAR charts scaled for viewing at 100cm. The size of the letters is shown in LogMAR units in the left column and Snellen format in the right column.Rotating the iPod/iPhone displays logMAR charts with a variety of optotypes including British, Sloan and tumbling E.

Near task simulator: One of the purposes of near vision testing is to ensure that a patient has adequate vision to perform everyday tasks such as reading a newspaper, yellow pages, maps etc.iChart 2000 contains a selection of such images. The magnification of these images can be adjusted by tapping the screen and selecting “Pan and zoom” from the menu. The image can then be moved around by simply moving your finger over the screen. The magnification can be changed by moving two fingers together or apart while touching the screen.

Binocularity: The Binocularity test is designed to assess the ability of the brain to integrate information from both eyes. The first two letters are seen by the right eye (assuming the red filter is in front of the right eye), the middle letter is seen by both eyes and the last two letters are seen by the left eye.The patient is asked to read the letters. Patients with good binocularity will read the complete words. If a patient reads CHA it implies that they are suppressing the left eye while reading AIN suggests that they are suppressing the right eye. Some grading of binocular status is possible by recording the smallest word that can be read completely.

Amsler charts: The Amsler grid is designed to detect subtle disturbances within the centre of the visual field and is particularly useful for patients with macula degeneration. A variety of grids are displayed to test different aspects of visual function.Rotating the iPod/iPhone changes the format of the grids. The patient can draw directly on the grid and the resultant image can be emailed to a computer to be printed.

Near duochrome test: A variety of images can be displayed against a duochrome (red/green) background. This can be used to assess accommodative lag/lead in younger patients and to fine-tune presbyopic corrections for older patients.

Near fixation: A series of images are included for the patient to fixate on while the optometrist is performing various tests, for example a cover test.The images (letters, crosses, cartoon characters) can be made to change automatically to form a slideshow by tapping on the screen and selecting “Slideshow” from the menu. The timing and transition between images can be changde from the main Settings menu.

This group displays a series of images and a video to help explain various conditions and solutions to patients. The magnification of these images can be adjusted by tapping the screen and selecting “Pan and zoom” from the menu. The image can then be moved around by simply moving your finger over the screen. The magnification can be changed by moving two fingers together or apart while touching the screen. You may also draw on the screen by tapping the screen and selecting Draw from the menu, then simply drawing with your finger on the screen.The images are divided into five self explanatory categories.

Eye diagrams: Selecting Eye diagrams displays a series of model eyes to help explain the general anatomy of the eye.

Eye disease: Selecting Eye disease displays a series of images of eyes with various eye diseases and conditions.

Visual Acuity Converter: This calculator converts visual acuity measurements from one format to another.For example, to calculate the LogMAR equivalent of 6/12, select Snellen (m) and dial in 6/12 and select Done. The screen will be automatically updated to show the equivalent to 6/12 in each of the other formats.To convert from one of the other formats back to Snellen (m), simply select the corresponding format and repeat the process.

LogMAR Scorer: A LogMAR chart is superior in design to a Snellen chart in a number of respects. However, scoring a LogMAR chart can be confusing for the novice. This tool is designed to assist during this learning phase.Simply enter the number of letters that the patient reads correctly on each row and the LogMAR score will be calculated automatically and displayed at the bottom of the screen.

Vertex Distance Calculator: This tool calculates the equivalent power of a sphero-cylindrical lens on the eye taking account of the vertex distance. This can be useful when fitting contact lenses for patients with higher prescriptions

Toric Contact Lens Over-Refraction Calculator: This tool calculates the residual refractive error when an over-refraction is carried out when wearing a toric soft contact lens.Enter the prescription of the toric contact lens in the box labelled CL Rx.Enter the over-refraction results in the box labelled Over Rx.Enter the Vertex distance of the trial frame in the third box.The program will then automatically resolve the two prescriptions and display an estimate of the prescription of the contact lens which should render the patient emmetropic.

Transposition Calculator: This calculator transforms a spectacle prescription from a minus cylinder to plus cylinder format or vice versa.Enter the prescription in either plus or minus cylinder format and the prescription will automatically appear in the alternative format in the other box.